What Is a Biliary Stent?

The biliary system has the functions of secreting, storing, concentrating, and transporting bile, and it has an important role in regulating the excretion of bile into the duodenum. Malignant biliary obstruction caused by malignant tumors such as cholangiocarcinoma, liver cancer, pancreatic cancer and metastatic cancer has a high incidence, and it is often advanced when found. Implantation of a biliary stent into a narrow or obstructed site is currently a better method for treating biliary obstruction.

The biliary system has the functions of secreting, storing, concentrating, and transporting bile, and it has an important role in regulating the excretion of bile into the duodenum. Malignant biliary obstruction caused by malignant tumors such as cholangiocarcinoma, liver cancer, pancreatic cancer and metastatic cancer has a high incidence, and it is often advanced when found. Implantation of a biliary stent into a narrow or obstructed site is currently a better method for treating biliary obstruction.

1. Biliary Stent 1. Introduction

The biliary system has the functions of secreting, storing, concentrating, and transporting bile, and it has an important role in regulating the excretion of bile into the duodenum. The bile ducts transport bile to the gallbladder and duodenum. Capillary bile ducts play an important role in regulating bile flow and composition. The gallbladder has the functions of concentration, storage, excretion of bile and secretion. Bile has the following main physiological functions: (1) Emulsified fat: After the bile salt enters the intestine, it combines with fat in food to form fat particles that are soluble in water, which is beneficial to the absorption of intestinal mucosa. (2) Promote the absorption of fat-soluble vitamins. Conducive to the absorption of fats, cholesterol and vitamins A, D, E, K. (3) Inhibition of intestinal pathogenic bacteria growth and endotoxin production. (4) Stimulate bowel movements.

Figure 1. Schematic diagram of the biliary system

Malignant biliary obstruction caused by malignant tumors such as cholangiocarcinoma, liver cancer, pancreatic cancer and metastatic cancer has a high incidence, and it is often advanced when found. Liver transplantation has now become the most effective method for treating end-stage liver disease, but the incidence of biliary complications is still high after surgery. According to statistics, it is 10% to 30%. The mortality rate is 10%, which affects long-term survival of patients. One of the important factors. The biliary reconstruction technique plays an important role in liver transplantation, and its success is an important factor affecting the incidence of biliary complications after liver transplantation.

Implantation of a biliary stent into a narrow or obstructed site is currently a better method for treating biliary obstruction. In complex biliary tract reconstruction, the application of biliary stent tube still cannot be ignored, especially in the case of unsatisfactory biliary tract reconstruction, it is necessary to consider the indwelling biliary stent tube. The biliary stent can not only reduce pressure drainage, support, and facilitate biliary healing It also facilitates the observation of bile and postoperative biliary angiography. Some studies have confirmed that indwelling stent tubes after anastomosis is a very important factor to avoid biliary complications and can play a role in reducing biliary complications, especially in complex and difficult biliary reconstruction. In the process of biliary reconstruction of liver transplantation, biliary stent tubes may not be left for patients with good biliary conditions, but for some complicated biliary tract reconstructions, different types of biliary stent tubes can be selected according to different conditions during the operation to facilitate biliary healing. Reduce biliary complications after liver transplantation.

2. Biliary stent 2. Features of titanium nickel shape memory alloy biliary stent

Figure 2. Titanium-nickel shape memory alloy biliary stent

At present, the most widely used biliary stent is a braided mesh stent made of titanium and nickel shape memory alloy (as shown in Figure 2). The shape is a straight cylinder and one or both ends are bell mouths. Biliary stenting is a minimally invasive treatment for malignant biliary obstruction. It can be repeated and can effectively relieve malignant biliary obstruction. Its effect is comparable to surgical shunt surgery. Titanium-nickel shape memory alloy biliary stent is generally self-expanding. Observe the expansion of the stent when it is placed, and expand it with a balloon if necessary. It is suitable for extrahepatic common bile duct obstruction or stenosis caused by various malignant lesions. Has the following advantages:

(1) The titanium-nickel memory alloy self-expanding biliary tract and anastomotic stent have excellent biocompatibility and corrosion resistance, and have unique memory characteristics and super elasticity. The inner stent is in a softened state at 0-10 ° C (ice water), changes its shape within a certain range, and is placed in a dispenser not greater than 10F; the inner stent is pushed out above 33 ° C and can immediately return to its original shape, resulting in Continuous soft radial expansion force acts on the inner wall of the biliary tract to restore the unobstructed stenosis. Its radial supporting force is greater than 6 N.

(2) The inner stent has good superelasticity at body temperature, can fluctuate and fluctuate with normal biliary peristalsis, so that the biliary tract is kept open and free of discomfort.

(3) The two ends of the inner stent are small arcs, which will not damage the bile duct wall. The operation is simple and the effect is exact.

(4) Prevent bacterial infection and stent blockage caused by bile deposits.

Biliary stent extended reading:

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[15] Chi Haiben, Gao Debao, Wang Yan. Treatment of giant bile duct stones with biliary stent [J]. Tianjin Medical Journal, 2014, 9 (42): 923-925